The Symphony No. 66 in B flat major (Hoboken I/66) is a symphony by Joseph Haydn. The time of composition is uncertain, with one speculation from around 1775–1776.[1] The symphony is scored for two oboes, two bassoons, two horns and strings.[2]
L.P. Burstein has noted Haydn's use of the VII♯ chord and the VII♯ → V progression in the first movement.[3] A.P. Brown has noted how Haydn reworked material from the symphony's first movement into other compositions, including an overture in D and two other symphonies.[4]